From the Guidelines
Medications that can prolong the QT interval include antiarrhythmics, antipsychotics, antibiotics, antidepressants, antiemetics, and others, and it is essential to check baseline QTc intervals, monitor electrolytes, and consider patient risk factors to minimize the risk of developing Torsades de Pointes.
Medications that Prolong QT Interval
The following medications can prolong the QT interval:
- Antiarrhythmics: amiodarone, sotalol, procainamide, disopyramide, dofetilide, ibutilide, quinidine 1
- Antipsychotics: haloperidol, chlorpromazine, mesoridazine, thioridazine, pimozide 1
- Antibiotics: clarithromycin, erythromycin, halofantrine, pentamidine, sparfloxacin, azithromycin, ciprofloxacin, moxifloxacin 1, 2
- Antidepressants: citalopram, escitalopram 2
- Antiemetics: domperidone, droperidol, ondansetron 1, 2
- Others: methadone, hydroxychloroquine, arsenic trioxide, bepridil, cisapride 1, 2 ### Risk Factors for Torsades de Pointes Risk factors for Torsades de Pointes include:
- Female gender
- Hypokalemia
- Bradycardia
- Recent conversion from atrial fibrillation
- Congestive heart failure
- Digitalis therapy
- High drug concentrations
- Rapid rate of intravenous drug administration
- Baseline QT prolongation
- Ventricular arrhythmia
- Left ventricular hypertrophy
- Congenital long QT syndrome
- Certain DNA polymorphisms
- Severe hypomagnesemia
- Concomitant use of 2 or more drugs that prolong the QT interval 1 ### Management When prescribing these medications, it's essential to:
- Check baseline QTc intervals via ECG
- Monitor electrolytes (especially potassium and magnesium)
- Avoid combining multiple QT-prolonging drugs
- Consider patient risk factors
- Educate patients about symptoms of arrhythmias, including palpitations, dizziness, and syncope, which warrant immediate medical attention 1, 2
From the FDA Drug Label
Like many other drugs (including all other class IA antiarrhythmics), quinidine prolongs the QTC interval, and this can lead to torsades de pointes, a life-threatening ventricular arrhythmia Torsade de Pointes arrhythmias in patients with VT/VF were dose related, as was the prolongation of QT (QTc) interval Fluoroquinolones, macrolide antibiotics, and azoles are known to cause QTc prolongation. There have been reports of QTc prolongation, with or without TdP, in patients taking amiodarone when fluoroquinolones, macrolide antibiotics, or azoles were administered concomitantly
The medications that prolong the QT interval are:
- Quinidine
- Sotalol
- Amiodarone (especially when used with other medications that prolong the QT interval, such as fluoroquinolones, macrolide antibiotics, and azoles)
- Disopyramide
- Procainamide
- Fluoroquinolones
- Macrolide antibiotics
- Azoles These medications can increase the risk of torsades de pointes, a life-threatening ventricular arrhythmia. 3, 4, 5
From the Research
Medications that Prolong the QT Interval
The following medications have been reported to prolong the QT interval, which can increase the risk of torsades de pointes and other life-threatening arrhythmias:
- Antiarrhythmic drugs: + Amiodarone 6, 7, 8 + Sotalol 6, 7, 8 + Quinidine 6, 7, 8, 9, 10 + Procainamide 6, 7, 8, 9, 10 + Ibutilide 6 + Disopyramide 6 + Dofetilide 7 + Flecainide 7
- Macrolide and fluoroquinolone antibiotics 6
- Antipsychotic and antidepressant drugs 6
- Serotonin agonists of the triptan class 6
- Cisapride 6
- Dolasetron 6
Factors that Increase the Risk of QT Prolongation
Several factors can increase the risk of QT prolongation, including: